N-[4-(3-Amino-1H-indazol-4-yl)phenyl]-N′-(2-fluoro-5-methylphenyl)urea (ABT-869) belongs to a family of protein tyrosine kinases (PTKs) which catalyze the phosphorylation of specific tyrosine residues in cellular proteins. Aberrant or excessive PTK activity has been observed in many disease states including benign and malignant proliferative disorders and diseases resulting from inappropriate activation of the immune system.
Crystallinity of hydrates of ABT-869 may effect, among other physical and mechanical properties, their stability, solubility, dissolution rate, hardness, compressibility and melting point. Because ease of manufacture and formulation of ABT-869 is dependent on some, if not all, of these properties, there is an existing need in the chemical and therapeutic arts for identification of crystalline forms of ABT-869 and ways to reproducibly make them.